1. Field of the Invention
The present invention relates generally to turntables and, more particularly, to a turntable allowing easy assembly of a magnetizing yoke on which a clamping magnet is seated to clamp a disc.
2. Description of the Related Art
As well known to those skilled in the art, a turntable is mounted to a disc drive device, and is rotated by a drive means including a spindle motor, thus rotating a disc mounted on the turntable. An example of a turntable is shown in FIG. 5.
As shown in FIG. 5, a conventional turntable 200 includes a main body 210 and a ball cover 280 which covers the lower portion of the main body 210.
The main body 210 includes a central guide part 220 and an annular balancing part 250. The central guide part 220 serves to guide the center of the disc, thus helping seat the disc on the turntable. The annular balancing part 250 extends integrally from the central guide part 220 in a circumferential direction thereof, and prevents imbalance caused by eccentricity of the disc when it is rotated.
The central guide part 220 has on a center thereof a shaft mounting hole 221 so that a rotating shaft of a drive means is inserted into the shaft mounting hole 221. An annular opening 222 is formed outside the shaft mounting hole 221.
A magnetizing yoke 230 is disposed in the annular opening 222, and a clamping magnet 240 for clamping the disc is provided on the yoke 230. In this case, protrusions 223 which protrude from the opening 222 penetrate the magnetizing yoke 230. One end of each protrusion 223 is pressed through heat fusion or the like, in order to secure the magnetizing yoke 230 to the central guide part 220.
Annular partition walls 251 and 252 protrude from the lower surface of the annular balancing part 250, thus defining space 254 for storing a plurality of balls 260 for balancing.
The ball cover 280 is provided to prevent the balls 260 from escaping to the outside. The outer wall of the ball cover 280 is inserted into a gap between the partition walls 251 and 252, so that the ball cover 280 is coupled to the balancing part 250.
However, the conventional turntable 200 constructed as described above is problematic in that the protrusions 223 must be pressed through heat fusion or the like to couple the magnetizing yoke 230 to the turntable 200, and thus it is difficult to assemble the magnetizing yoke 230 with the turntable 200. The conventional turntable has another problem in that after the magnetizing yoke 230 has been assembled with the turntable 200, it is difficult to replace the magnetizing yoke 230 with another one.